I think it's actually Doncic's ability to go and stop, if that's a thing, that gets him open so much. I've struggled to spot what it is about him that's so difficult to defend, but the one thing I see frequently is him stopping on a dime while driving to the basket, while the defender(s) flies by. Few players can control their momentum like that.
How he creates so many driving lanes in the first place, I haven't quite figured out yet. It's probably a mix of his threat as a passer and shooter, combined with presumably deceptive strength.
